Digital implementation of nonuniformity correction for IRFPAs

All IRFPAs require nonuniformity correction. Although two- point or multi-point correction algorithms may correct the nonuniformity of IRFPAs they can be limited by pixel nonlinearities and instabilities. So adaptive nonuniformity correction techniques are needed. Many researchers develop the methods of real-time correction based the scene being viewed. The nonuniformity correction process is completed in IRFPA sensor named smart FPA. However, the smart IRFPA is developing. The purpose of this paper is to describe a digital signal processing electronics for the nonuniformity correction. It includes ADSP21060 digital signal processor, 8751 chip and display circuit module. The image data from IRFPA are put into the dual RAM. The ADSP21060 DSP completes the nonuniformity correction function while the 8751 chip operates control function. At the same time, the correction results will be displayed on a monitor. The neural networks algorithms and the constant-statistics algorithm are tested in our digital implementations. When the image size is 60*97, processing time per frame is 14.75 millisecond for the neural network algorithm and it is 12.65 millisecond for the constant-statistics algorithm. Measured results show that digital processing system designed by us may achieve demand of real-time nonuniformity correction based the scene for small IRFPAs.